Packing nut lock and method of use

ABSTRACT

An apparatus for preventing a threaded nut from unscrewing from a threaded bore of a device. The threaded nut has a circular periphery containing a plurality of apertures. The apparatus has a body with a first pin configured to insert into one of the apertures of the threaded nut, and a retainer that releasably holds the first pin within the aperture.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No. 13/152,076, filed Jun. 2, 2011, now U.S. Pat. No. 9,157,468, entitled “Packing Nut Lock and Method of Use”, which claims priority to U.S. Provisional Application No. 61/351,537 filed on Jun. 4, 2010, entitled “Packing Nut Lock and Method of Use,” the disclosures of each of which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

This disclosure relates in general to reciprocating pumps, and in particular, to a packing nut lock for a reciprocating pump.

BACKGROUND OF THE DISCLOSURE

In oil field operations, reciprocating pumps are often used for various purposes. Some reciprocating pumps, generally known as “service pumps,” are typically used for operations such as cementing, acidizing, or fracing a well. Typically, these service pumps run for relatively short periods of time, but they operate on a frequent basis. Often they are mounted to a truck or a skid for transport to various well sites. A pump might operate several times a week. In many applications, several pumps are connected in parallel to a single flow line.

High pressure pumps are widely used in the petroleum industry for a variety of field operations relating to oil and gas wells. Such pumps deliver a fluid or slurry, which may carry solid particles (e.g., a sand proppant), at pressures up to 20,000 psi. A common type is a positive displacement pump having one or more plungers reciprocally movable in a corresponding pump chamber. Each chamber has an intake port for receiving fluid, a discharge port for exhaust, and a one-way flow valve in each port for preventing reverse flow. These valves require frequent maintenance.

With the many different ports and chambers in a high pressure pump, it is advantageous to ensure that threaded assemblies are securely threaded into the corresponding bores of the pump assembly. Unfortunately, many of these threaded assemblies are prone to inadvertently loosen. The pump experiences substantial vibration during operation at high power settings such that the threaded assemblies may overcome their initially applied torque and begin to “back out”, or rotate in a loosening direction. With respect to many of the threaded assemblies, should the assemblies continue to loosen, the closure, and in some instances, a quantity of high pressure fluid may be ejected from the pump housing and potentially cause damage or injury. Consequently, safety regulations demand that operators respond to any loosening of threaded assemblies by stopping the pump. That degrades efficiency and can necessitate the expense of a back-up pump for continuing a pumping operation while the primary pump is shut down.

SUMMARY

In a first aspect, there is provided a locking apparatus for preventing a nut from disengaging from a bore of a device. The locking apparatus includes a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces. The locking apparatus also includes non-movable pin extending from the bottom surface, the non-movable pin insertable into a first aperture of a nut, and a retractable pin movable along a central axis of the aperture between an engaged position in which the retractable pin extends at least partially from the bottom surface, for positioning the retractable pin into a second aperture of a nut, and a retracted position, for removing the retractable pin from a second aperture of a nut to facilitate removal of the body. In addition, the apparatus includes a shank extending from the top surface of the body.

In certain embodiments, the central axis is in a same plane as an axis of the non-movable pin.

In other certain embodiments, the central axis intersects an axis of the non-movable pin.

In yet another embodiment, the apparatus also includes a resilient member to bias the retractable pin toward the engaged position.

In still another embodiment, the locking apparatus further includes a resilient member disposed within the shank, the resilient member biasing the retractable pin toward the engaged position.

In yet another embodiment, the body is arcuate.

In other certain embodiments, the locking apparatus further includes a planar surface on an outer end of the shank, opposite the body, the planar surface adapted to transfer a rotational force to the nut.

In certain embodiments, the locking apparatus further includes a handle extending from the retractable pin to retract the retractable pin.

In a second aspect, there is provided a method of manufacturing a locking apparatus for preventing a nut from disengaging from a bore of a device. The method includes providing a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces. Additionally, the method includes securing a fixed pin to the body such that the fixed pin extends in fixed relation from a bottom surface of the body and is configured to be insertable into a first aperture of a nut, and positioning a retractable pin within the aperture such that the retractable pin is movable along a central axis of the aperture between an engaged position, for positioning the retractable pin into a second aperture of a nut, and a retracted position, for removing the retractable pin from a second aperture of a nut to facilitate removal of the body. The method further includes securing a shank to a top surface of the body opposite the bottom surface.

In certain embodiments, the method includes providing a body having an aperture such that the central axis of the aperture is in a same plane as an axis of the fixed pin.

In other certain embodiments, the method includes providing a body having an aperture such that the central axis of the aperture intersects an axis of the fixed pin.

In yet another embodiment, the method further includes providing a resilient member to bias the retractable pin toward the engaged position.

In still another embodiment, the method includes positioning a resilient member inside the shank, the resilient member biasing the retractable pin toward the engaged position.

In other certain embodiments, the method includes securing the fixed pin to an arcuate body.

In certain embodiments, the method includes forming a planar surface on an outer end of the shank, opposite the body, the planar surface configured to transfer a rotational force to the nut.

In other certain embodiments, the method includes securing a handle to the retractable pin to retract the retractable pin.

In a third aspect, there is provided a reciprocating pump assembly including a reciprocating pump, a threaded member in engagement with a threaded bore on the reciprocating pump, and a lock for resisting movement of the threaded member relative to the reciprocating pump. The lock includes a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces and a first pin non-rotatably attached to and extending from the bottom surface of the body for engagement with the threaded member. The lock further includes a second pin at least partially disposed within the aperture and movable relative to the body between an engaged position, where at least a portion of the second pin is configured to engage the threaded member to secure the body to the threaded member, and a retracted position, to facilitate separation of the body from the threaded member. The lock also includes a shank extending from the top surface.

In certain embodiments, the assembly includes a resilient member to bias the second pin toward the engaged position.

In other certain embodiments, the assembly further includes a resilient member disposed within the shank, the resilient member biasing the second pin toward the engaged position.

In yet another embodiment, the assembly further includes a handle extending from the second pin to retract the second pin.

In still another embodiment, the threaded member includes at least one aperture to receive at least one of the first or second pin therein.

In a fourth aspect there is provided a nut lock having a main body having a top surface, an opposed bottom surface, and an aperture extending at least partially through the main body and a shank extending from a top surface of the main body. The apparatus further includes a non-movable member extending from the bottom surface of the main body and configured to engage a nut and a movable member movable between an engaged position, wherein the movable member extends from the main body and is configured to engage a nut such that rotation of a nut is prevented, and a disengaged position, wherein the movable member is at least partially retracted with respect to the main body and is configured to be disengaged from a nut.

Other aspects, features, and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of any disclosures disclosed.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings facilitate an understating of the various embodiments.

FIG. 1 is an elevational view of a reciprocating pump assembly;

FIG. 2 is a top plan schematic view of the reciprocating pump assembly of FIG. 1;

FIG. 3 is a sectional view of the pump assembly shown in FIG. 1;

FIG. 4 is a front plan view of a packing nut lock in accordance with the present disclosure;

FIG. 5 is a perspective view of the packing nut lock of FIG. 4;

FIG. 6 is a spring pin assembly in accordance with the present disclosure;

FIG. 7 is a sectional view of a portion of a reciprocating pump assembly in accordance with the present disclosure, with a packing nut lock installed in a disengaged position;

FIG. 8 is a sectional view of a portion of a reciprocating pump assembly in accordance with the present disclosure, with a packing nut lock installed in an engaged position;

FIG. 9 is a sectional view of a portion of a reciprocating pump assembly in accordance with the present disclosure, with a packing nut lock installed in an engaged position;

FIG. 10 is a perspective view of a portion of a reciprocating pump assembly in accordance with the present disclosure, with a packing nut lock installed and in an engaged position, and in contact with a stay rod;

FIG. 11 is a front plan view of a packing nut lock in accordance with an alternate embodiment of the present disclosure;

FIG. 12 is a perspective view of the packing nut lock of FIG. 11; and

FIG. 13 is a sectional view of the packing nut lock in accordance with an alternate embodiment of the present disclosure, and taken along the line A-A of FIG. 11.

FIG. 14 is an exploded view of a spring pin assembly in accordance with an alternate embodiment of the present disclosure;

FIG. 15 is a perspective view of a packing nut lock and tool in accordance with an alternate embodiment of the present disclosure;

FIG. 16 is an additional perspective view of the packing nut lock and tool of FIG. 15, connected to a packing nut; and

FIG. 17 is a sectional view of the packing nut lock and tool taken along the line B-B of FIG. 16.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 3, a reciprocating pump assembly or pump 12 includes a crankshaft housing 13 that comprises the outer surface of the reciprocating pump 12. A plurality of stay rods 15 attach to a side of the crankshaft housing 13 and extend to a fluid cylinder housing 17. Each cylinder typically includes a fluid inlet 19 and a fluid outlet 21. As best shown in FIGS. 1 through 3, an access bore cover 22 connects to an end of the cylinder housing 17, opposite the plurality of stay rods 15. The pump 12 can easily be mounted to a trailer that can be towed between operational sites, or to a skid for use in offshore operations. Accordingly, a pump assembly may include the pump 12 mounted directly to the ground or a support structure, a skid, a trailer, etc.

Referring to FIG. 2, the plurality of stay rods 15 are segmented into three portions, each portion having multiple stay rods 15, and each portion comprising a plunger throw 23. The reciprocating pump 12 (as shown in FIG. 2) has three plunger throws 23, a configuration which is commonly known as a triplex pump, but the stay rod can also be segmented for five plunger throws, a configuration which is commonly known as a quintuplex pump. The present description is directed to a triplex pump, but as will be readily apparent to those skilled in the art, the features and aspects described are easily applicable for a quintuplex pump or other types of pumps. Each plunger throw 23 houses a plunger or pony rod 33 (FIG. 3) that extends to the cylinder housing 17. As shown in FIG. 2, each of the plunger throws 23 extend in the same longitudinal direction as each other from the crankshaft housing 13.

Referring to FIG. 3, a portion of the reciprocating pump 12 that is housed within the crankshaft housing 13 is shown. The crankshaft housing 13 houses a crankshaft 25, which is typically mechanically connected to a motor (not shown). The motor rotates the crankshaft 25 in order to drive the reciprocating pump 12. In one embodiment, the crankshaft 25 is cammed so that fluid is pumped from the cylinder housing 17 at alternating times. As will be readily apparent by those skilled in the art, alternating the cycles of pumping fluid from the cylinder housing 17 helps minimize the primary, secondary, and tertiary (et al.) forces associated with the reciprocating pump 12.

In one embodiment, a gear 24 is mechanically connected to the crankshaft 25 and is rotated by the motor through a gear 26. A connector rod 27 connects to a crosshead 29 through a crosshead pin 31, which holds the connector rod 27 laterally relative to the crosshead 29. The connector rod 27 pivots about the crosshead pin 31 as the crankshaft 25 rotates with the other end of the connector rod 27. The pony rod 33 extends from the crosshead 29 in a longitudinally opposite direction from the connector rod 27. The connector rod 27 and the crosshead 29 convert rotational movement of the crankshaft 25 into longitudinal movement of the pony rod 33.

A plunger 35 is connected to the pony rod 33 for pumping the fluid which passes through the cylinder housing 17 during operation of the pump 12. A packing 36 surrounds the plunger 35. A packing nut 38 is threaded into the cylinder housing 17, and acts to maintain the packing 36 in the proper position within the packing bore 37. A number of holes or apertures 40 (FIGS. 7, 8, and 10) extend along the outer diameter of the rim of the packing nut 38. The holes 40 are for engagement by a spanner to tighten and loosen the packing nut 38. When properly positioned, the packing 36 and the packing nut 38 maintain the necessary pressure between the plunger 35 and the packing 36, and prevent the packing bore 37 from leaking.

The cylinder housing 17 connects to the ends of the stay rods 15, extending away from the crankshaft housing 13 (FIG. 1). The cylinder housing 17 includes a plurality of interior or cylinder chambers 39, which is where the plungers 35 compress the fluid being pumped by the reciprocating pump 12. The cylinder housing 17 also typically includes an inlet valve 41 and an outlet valve 43. The valves 41, 43 are usually spring-loaded valves and are actuated by a predetermined differential pressure. The inlet valve 41 actuates to control fluid flow through the fluid inlet 19 into the cylinder chamber 39, and the outlet valve 43 actuates to control fluid flow through the fluid outlet 21 from the cylinder chamber 39. Other valve arrangements and configurations of the fluid end of equivalent functionality are envisaged.

The plunger 35 reciprocates, or moves longitudinally toward and away from the cylinder housing 17 as the crankshaft 25 rotates. As the plunger 35 moves longitudinally away from the cylinder chamber 39, the pressure of fluid inside the chamber 39 decreases, creating a differential pressure across the inlet valve 41, which actuates the valve 41 and allows the fluid to enter the cylinder chamber 39 from the fluid inlet 19. The fluid being pumped enters the cylinder chamber 39 as the plunger 35 continues to move longitudinally away from the cylinder housing 17 until the pressure difference between the fluid inside the cylinder chamber 39 and the fluid in the fluid inlet 19 is small enough for the inlet valve 41 to actuate its closed position. On the return stroke as the plunger 35 begins to move longitudinally towards the cylinder housing 17, the pressure on the fluid inside of the cylinder chamber 39 begins to increase. Fluid pressure inside the cylinder chamber 39 continues to increase as the plunger 35 approaches the cylinder housing 17 until the differential across the outlet valve 43 is large enough to actuate the outlet valve 43 and allow the fluid to exit the cylinder housing 17 through the fluid outlet 21. In one embodiment, fluid is only pumped across one side of the plunger 35; therefore, the reciprocating pump 12 is a single-acting reciprocating pump. As the operation of the pump 12 is conventional, it will not be described in further detail. During operation of the pump 12, vibration and reciprocating forces from the plunger 35 may cause the packing nut 38 to loosen or back out. As the packing nut 38 backs out, the packing 36 is affected, which may result in pressure differentials and leakage of fluid from the packing bore 37.

Referring to FIGS. 4 and 5, in this embodiment, a packing nut lock 67 is comprised of a main body 69 having a generally elongate, arcuate shape. In this embodiment, the main body 69 generally subtends an angle of around one sixth of a circle and has a top surface 71 and a bottom surface 73. The bottom surface 73 of the main body 69 is substantially geometrically complimentary to the rim of the packing nut 38 and is adapted to be in abutting contact with a portion of the outer diameter of the rim of the packing nut 38 (FIGS. 7 and 8). Two apertures 75, 77 are located in and extend through opposite end portions of the main body 69, with each aperture 75, 77 extending from the top surface 71 through to the bottom surface 73. In this embodiment, a fixed cylindrical pin 79 having an upper flange portion 81 with a greater diameter than a lower portion 83, is inserted into and passes through one of the apertures 75. In this embodiment, the cylindrical pin 79 is welded to the main body 69. However, in additional embodiments, the cylindrical pin 79 may be cast as one member with main body 69, or may be connected to main body 69 by other means. The lower portion 83 of the fixed cylindrical pin 79 is adapted to be inserted into one of the holes 40 that extend around the outer diameter of the rim of packing nut 38, when the packing nut lock 67 is engaged (FIG. 8).

Although the packing nut 38 illustrated with the current embodiment is circular in shape, the packing nut 38 may have alternative shapes. For example, the packing nut 38 may be hexagonal, square, etc., in additional embodiments. In such additional embodiments, the main body 69 of the packing nut lock 67 may be shaped to be geometrically complimentary to the shape of the packing nut 38. For example, if the packing nut 38 were hexagonal in shape, the main body 69 of the packing nut lock 67 would be geometrically complimentary to the hexagonal shape of the packing nut 38.

A spring pin assembly 85 is connected to the top surface 71 of the main body 69, above the other aperture 77. Referring to FIG. 6, the spring pin assembly 85 is comprised of a collar 87, a center pin 89, a resilient member or spring 91, a retaining nut 93, and a handle 95. In this embodiment, the collar 87 is a hollow bodied cylindrical member having a closed end 97 and an open end 99. The closed end 97 of the collar 87 has an aperture 101 located in and extending therethrough that is aligned with the aperture 77 in the main body 69. In this embodiment, the collar 87 is welded to the main body 69. However, in additional embodiments, the collar 87 may be cast as one member with the main body 69, or may be connected to the main body 69 by other means. In this embodiment, the inner surface of the open end 99 of the collar 87 has threads located therein. An elongated aperture or slot 103 is located in and extends through the cylindrical collar 87 along a portion of its outer surface.

The center pin 89 has a cylindrical medial flange portion 105 having a diameter that is slightly less than the inner diameter of the collar 87, such that the center pin 89 is positioned within the collar 87. In this embodiment, a threaded aperture 107 is located in and extends through the medial flange portion 105 of the center pin 89, substantially perpendicular to the axis of the center pin 89. A cylindrical locking pin portion 109 of the center pin 89 has a smaller diameter than the flange portion 105 and extends axially downward therefrom. The locking pin portion 109 of the center pin 89 is adapted to be inserted into one of the holes 40 that extend along the outer diameter of the rim of the packing nut 38 when the packing nut lock 67 is engaged (FIG. 8). A cylindrical guide pin portion 111 of the center pin 89 has a diameter which is smaller than the flange portion 105 and smaller than the locking pin portion 109, and extends axially upward from the flange portion 105, in a direction opposite to the locking pin portion 109.

Although the holes 40 of the packing nut 38 illustrated with the current embodiment are circular in shape, the holes 40 may have alternative shapes. For example, the holes 40 may be hexagonal, square, etc. in additional embodiments. In such additional embodiments, the fixed pin 79 and the center pin 89 may be shaped to be geometrically complimentary to the shape of the holes 40 in the packing nut 38. For example, if the holes 40 of the packing nut 38 were hexagonal in shape, the fixed pin 79 and the center pin 89 of the packing nut lock 67 would be geometrically complimentary to the hexagonal shape of the holes 40 of the packing nut 38.

Referring to FIG. 9, in this embodiment the handle 95 is cylindrical and has threads located in the exterior surface of one of its ends 113. The threaded end 113 of the handle 95 threadingly engages with the threaded aperture 107 in the flange portion 105 of the center pin 89, thereby connecting the handle 95 and the center pin 89. The handle 95 extends radially outwardly from the flange portion 105 of the center pin 89 and also passes through the elongated aperture or slot 103 in the collar 87. The handle 95 extends a desired distance radially outward from the collar 87. The handle 95 is adapted to move vertically within the aperture 103 of the collar 87 to thereby move the center pin 89, and in particular the locking pin portion 109, from an engaged position to a disengaged position.

The cap or retaining nut 93 has a first end 115 and a second end 117. In this embodiment, the retaining nut 93 is cylindrical and has threads on its exterior surface that are threadably engaged with the threads on the inner surface of the open end 99 of the collar 87. The retaining nut 93 thereby seals or caps the open end 99 of the collar 87 when the two are connected to one another. The second end 117 of the retaining nut 93 has an aperture 119 located therein with a diameter slightly larger than the diameter of the guide pin portion 111 of the center pin 89. The guide pin portion 111 of the center pin 89 is captured within the aperture 119 of the retaining nut 93. As the center pin 89, and in particular, the locking pin portion 109 is moved vertically upward from an engaged position to a disengaged position, the guide pin portion 111 of the center pin 89 travels further into the aperture 119 in the retaining nut 93.

In this embodiment, the spring 91 surrounds the guide pin portion 111 of the center pin 89 and abuts against the retaining nut 93 on one end and the flange portion 105 of the center pin 89 on the other end. The spring 91 acts to bias the center pin 89 into an engaged position, with the locking pin portion 109 of the center pin 89 extending fully outward through the aperture 77 in the main body 69 (FIGS. 4 and 5).

Referring to FIG. 9, in operation, once the packing 36 has been inserted around the plunger 35 within the packing bore 37, the packing nut 38 is threaded into the body of the cylinder housing 17. Referring generally to FIG. 7, a spanner (not shown) is inserted into holes or apertures 40 on the outer diameter of the rim of the packing nut 38, and the packing nut 38 is securely tightened. The packing nut lock 67 is then connected to the packing nut 38. The fixed cylindrical pin 79 is machined so that the smaller diameter portion 83 will fit into one of the holes 40 extending around the rim of the packing nut 38. The packing nut 67 is positioned so that the smaller diameter portion 83 of the fixed cylindrical pin 79 is positioned within one of the holes 40 of the packing nut 38. The center pin 89 of the spring pin assembly 85 is positioned in a disengaged position within the collar 87 by positioning the handle 95 to its most upward position within the elongated aperture 103. Force is maintained against the handle 95 to compress the spring 91 and to allow the center pin 89 to maintain the disengaged position. The guide pin portion 111 of the center pin 89 fully enters the aperture 119 in the retaining nut 93. The main body 69 of the packing nut lock 67 is positioned so that the bottom surface 73 is in abutting contact with the outer diameter of the rim of the packing nut 38, and the aperture 77 is positioned directly above another hole 40 in the packing nut 38.

Referring generally to FIGS. 8 and 9, once the packing nut lock 67 is properly positioned, the force is removed from the handle 95 of the spring pin assembly 85, and the spring 91 expands and pushes the center pin 89 downward relative to the collar 87. The locking pin portion 109 of the center pin 89 fully extends through the aperture 77 in the main body 69 of the packing nut lock 67 and engages another hole 40 in the packing nut 38. Based on the angles of the fixed cylindrical pin 79 and the center pin 89 relative to one another within the holes 40 of the packing nut 38, the packing nut lock 67 is securely engaged with the packing nut 38, and cannot be removed without disengaging the spring pin assembly 85.

Referring to FIG. 10, the spring pin assembly 85, and in particular, the collar 87 and the retaining cap 95, extend radially outward from the center of the packing bore 37 by a distance that is greater than or equal to the distance from the center of the packing bore to the stay rod 15. If the packing nut 38 begins to rotate relative to the housing 17, the spring pin assembly 85 makes contact with the stay rod 15, thereby preventing the packing nut lock 67 from rotating relative to the housing 17, and thus, also preventing the packing nut 38 from rotating any further relative to the housing 17. As a result, the packing nut lock 67 prevents the packing nut 38 from loosening and backing out of the packing bore 37.

Referring to FIGS. 11 and 12, in an alternate embodiment, a packing nut lock 121 is comprised of a main body 123 having a generally elongate, arcuate shape. In this alternate embodiment, the main body 123 generally subtends an angle of about one sixth of a circle and has a top surface 125 and a bottom surface 127. The bottom surface 127 of the main body 123 is substantially geometrically complimentary to the rim of the packing nut 38 and is adapted to be in abutting contact with a portion of the outer diameter of the rim of the packing nut 38. An aperture 131 is located in and extends through an end portion of the main body 123, with the aperture 131 extending from the top surface 125 through to the bottom surface 127. In this alternate embodiment, a fixed cylindrical pin 133 having an upper concave portion 135 with a lesser diameter than a lower portion 137, extends from the bottom surface 127 of the main body 123, opposite the end portion of the main body 123 through which the aperture 131 extends. In this alternate embodiment, the cylindrical pin 133 is cast as one member with the main body 123. However, in additional embodiments, the cylindrical pin 133 may be welded to the main body 123, or may be connected to the main body 123 by other means. The fixed cylindrical pin 133 is adapted to be inserted into one of the holes 40 that extend along the outer diameter of the rim of the packing nut 38 when the packing nut lock 121 is engaged.

A spring pin assembly 139 is connected to the top surface 125 of the main body 123, above the aperture 131. Referring to FIGS. 13 and 14, the spring pin assembly 139 is comprised of a collar 141, a center pin 143, a resilient member or spring 145, and a handle 147. In this embodiment, the collar 141 is a hollow bodied cylindrical member having a closed end 149 and an open end 151. The open end 151 of the collar 141 is aligned with the aperture 131 in the main body 123. In this alternate embodiment, the collar 141 is welded to the main body 123. However, in additional embodiments, the collar 141 may be cast as one member with the main body 123, or may be connected to the main body 123 by other means. An elongated aperture or slot 153 is located in and extends through the cylindrical collar 141 along a portion of its outer surface.

The center pin 143 is a cylindrical member having a diameter that is slightly less than the inner diameter of the collar 141, such that the center pin 143 is positioned within the collar 141. In this embodiment, a threaded aperture 155 is located in and extends through a medial portion of the center pin 143, substantially perpendicular to the axis of the center pin 143. An end portion 157 of the center pin 143 is adapted to be inserted into one of the holes 40 that extend around the outer diameter of the rim of the packing nut 38 when the packing nut lock 121 is engaged.

In this embodiment, the handle 147 is cylindrical and has threads located in the exterior surface of one of its ends 159. The threaded end 159 of the handle 147 threadingly engages the threaded aperture 155 in the medial portion of the center pin 143, thereby connecting the handle 147 and the center pin 143. The handle 147 extends radially outward from the center pin 143 before passing through the elongated aperture or slot 153 in the collar 141. The handle 147 extends a desired distance radially outward from the collar 141. The handle 147 is adapted to move vertically within the aperture 153 of the collar 141 to thereby move the center pin 143, and in particular, the end portion 157, from an engaged position to a disengaged position.

In this embodiment, the spring 145 is positioned within the collar 141 between the closed end 149 of the collar 141 and the center pin 143. The spring 145 acts to bias the center pin 143 in an engaged position, with the end portion 157 of the center pin 143 extending fully outward through the aperture 131 in the main body 123 (FIGS. 11 and 12).

In operation, the alternate embodiment packing nut lock 121 is installed on the reciprocating pump 12 and engaged/disengaged with the packing nut 38 just as for the first embodiment of a packing nut lock 67 described herein.

Referring to FIGS. 15 through 17, in an alternate embodiment, a packing nut lock and tool 161 is comprised of a main body 163 having a generally elongate, arcuate shape. The packing nut lock and tool 161 of this alternate embodiment may be employed similarly to the packing nut locks 67, 121 of the aforementioned embodiments set forth herein. The packing nut lock and tool 161 of this alternate embodiment may also be utilized with other portions of the reciprocating pump 12. For example, the packing nut lock and tool 161 may be utilized with the packing nut 38, a discharge flange, a gauge port, or any item that incorporate holes or apertures on the outer diameter of the rim of the item. For illustration purposes only, the packing nut lock and tool 161 shown in FIG. 15 will be discussed in relationship to the packing nut 38.

In this alternate embodiment, the main body 163 of the packing nut lock and tool 161 generally subtends an angle of around one fifth of a circle and has a top surface 165 and a bottom surface 167. The bottom surface 167 of the main body 163 is substantially geometrically complimentary to the rim of the packing nut 38 and is adapted to be in abutting contact with a portion of the outer diameter of the rim of the packing nut 38. Referring to FIG. 17, an aperture 169 is located in and extends through an end portion of the main body 163, with the aperture 169, extending from the top surface 165 through to the bottom surface 167. In this alternate embodiment, a fixed cylindrical pin 171 having an upper concave portion 173 with a lesser diameter than a lower portion 175, extends from the bottom surface 167 of the main body 163, opposite the end portion of the main body 163 through which the aperture 169 extends. In this alternate embodiment, the cylindrical pin 171 is cast as one member with the main body 163. However, in additional embodiments, the cylindrical pin 171 may be welded to the main body 163, or may be connected to main body 163 by other means. The fixed cylindrical pin 171 is adapted to be inserted into one of the holes 40 that extend along the outer diameter of the rim of packing nut 38 when the packing nut lock and tool 161 are engaged.

A cylindrical arm 176 extends from the top surface 165 of the main body 163 of the packing nut lock and tool 161, just above the fixed cylindrical pin 171. In this embodiment, the cylindrical arm 176 is cast as one member with the main body 163. However, in additional embodiments, the cylindrical arm 176 may be welded to the main body 163, or may be connected to the main body 163 by other means. In this embodiment, a substantially rectangular engagement member 177 is connected to the end of the cylindrical arm 176, opposite the main body 163 of the packing nut lock and tool 161. The substantially rectangular engagement member 177 has two substantially planar contact surfaces 178, 179 on opposite sides of and parallel to one another. The planar contact surfaces 178, 179 extend in a plane that intersects and is substantially perpendicular to the arc of the main body 163. The planar contact surface 178, 179 are adapted to act as a contact point for a force to be exerted on the packing nut lock and tool 161, for example, the force of a sledge hammer.

A spring pin assembly 181 is connected to the top surface 165 of the main body 163, above the aperture 169. Referring to FIG. 17, the spring pin assembly 181 is comprised of a collar 183, a center pin 185, a resilient member or spring 187, and a handle 189. In this embodiment, the collar 183 is a hollow bodied cylindrical member having a closed end 191 and an open end 193. The open end 193 of the collar 183 is aligned with the aperture 169 in the main body 163. In this alternate embodiment, the collar 183 is cast as one member with the main body 163. However, in additional embodiments, the collar 183 may be welded to the main body 163, or may be connected to the main body 163 by other means. An elongated aperture or slot 195 is located in and extends through the cylindrical collar 183 along a portion of its outer surface.

The center pin 185 is a cylindrical member having a diameter that is slightly less than the inner diameter of the collar 183, such that the center pin 185 is positioned within the collar 183. In this embodiment, a threaded aperture 197 is located in and extends through a portion of the center pin 185, substantially perpendicular to the axis of the center pin 185. An end portion 199 of the center pin 185 is adapted to be inserted into one of the holes 40 that extend along the outer diameter of the rim of the packing nut 38 when the packing nut lock and tool 161 is engaged.

In this embodiment, the handle 189 is cylindrical and has threads located in the exterior surface of one of its ends 201. The threaded end 201 of the handle 189 threadingly engages the threaded aperture 197 in the portion of the center pin 185, thereby connecting the handle 189 and the center pin 185. The handle 189 extends radially outward from the center pin 185 before passing through the elongated aperture or slot 195 in the collar 183. The handle 189 extends a desired distance radially outward from the collar 183. The handle 189 is adapted to move vertically within the aperture 195 of the collar 183 to thereby move the center pin 185, and in particular, the end portion 199, from an engaged position to a disengaged position.

In this embodiment, the spring 187 is positioned within the collar 183 between the closed end 191 of the collar 183 and the center pin 185. The spring 187 acts to bias the center pin 185 in an engaged position, with the end portion 199 of the center pin 185 extending fully outward through the aperture 169 in the main body 163. In this embodiment, a rib or brace structure 203 extends between the collar 183, the upper surface 165 of the main body 163, and the cylindrical arm 176. In this alternate embodiment, the rib or brace structure 203 is cast as one member with the main body 163, collar 183, and cylindrical arm 176. However, in additional embodiments, the brace structure 203 may be welded to the main body 163, collar 183, and cylindrical arm 176, or may be connected by other means. In this embodiment, a rib or brace structure 205 extends between the upper surface 165 of the main body 163 and the cylindrical arm 176. In this alternate embodiment, the rib or brace structure 205 is cast as one member with the main body 163 and with the cylindrical arm 176. However, in additional embodiments, the brace structure 205 may be welded to the main body 163 and to the cylindrical arm 176, or may be connected by other means.

In operation, the alternate embodiment packing nut lock and tool 161 is installed on the reciprocating pump 12 and engaged/disengaged with the packing nut 38 just as for the first embodiment of a packing nut lock 67 and also for the additional embodiment of a packing nut lock 121. However, in the packing nut lock and tool 161 of this embodiment, the cylindrical arm 176 and the substantially rectangular engagement member 177 extend radially outward from the center of the packing bore 37 a distance that is greater than or equal to the distance from the center of the packing bore to the stay rod 15 (items illustrated in FIG. 10 may be referred to). If the packing nut 38 begins to rotate relative to the housing 17, the cylindrical arm 176 and the substantially rectangular engagement member 177 may make contact with the stay rod 15, thereby preventing the packing nut lock and tool 161 from rotating relative to the housing 17, and thus, also preventing the packing nut 38 from rotating any further relative to the housing 17. As a result, the packing nut lock and tool 161 prevents the packing nut 38 from loosening and backing out of the packing bore 37.

In operation, the alternate embodiment packing nut lock and tool 163 may also be utilized to tighten and/or loosen an item that incorporate holes or apertures on the outer diameter of the rim of the item. For example, generally referring to FIG. 16, a spanner (not shown) may be inserted into holes or apertures 40 on the outer diameter of the rim of the packing nut 38, and the packing nut 38 may be tightened. However, referring to FIG. 17, to ensure that the packing nut 38 is securely tightened, the packing nut lock and tool 161 may be connected to the packing nut 38 by engaging the fixed cylindrical pin 171 and the center pin 185 with holes 40 in the packing nut 38. As discussed with respect to the packing nut lock 67, the center pin 185 is first retracted into the collar 183 using the handle 189 as the fixed cylindrical pin 171 is inserted into one of the holes 40 of the packing nut 38. Once the fixed cylindrical pin 171 is positioned within one of the holes 40 of the packing nut 38, the handle 189 of the center pin 185 is released, and the end portion 199 of the center pin 185 engages another hole 40 in the packing nut 38, thereby securely connecting the packing nut lock and tool 161 to the packing nut 38. Once the packing nut lock and tool 161 is connected to the packing nut 38, a force may be applied to one of the planar contact surfaces 178, 179 of the substantially rectangular engagement member 177. The force is applied at an angle substantially perpendicular to the planar contact surfaces 178, 179, thus resulting in a force that causes the packing nut lock and tool 161 to rotate about the axis of the packing bore. For example, the force may be applied by an operator engaging the planar contact surfaces 178, 179 with a sledge hammer. The force can be applied to the contact surfaces 178, 179 until the packing nut lock and tool 161 rotates a desired amount, and thus, the packing nut 38 is either tightened or loosed to the operator's liking. Depending upon whether the packing nut 38 is to be tightened or loosed, the force is applied to the corresponding contact surface 178, 179 of the packing nut lock and tool 161 to achieve the desired result, as illustrated in FIG. 17 by the items F1 and F2 illustrating the direction of the force applied, and the corresponding directions of rotation, R1 and R2.

The foregoing embodiment(s) described provide several operational advantages aimed at preventing backing off of the packing nut. When in place, the packing nut locks of the present disclosure maintain the necessary pressure between the plunger and the packing, and help to prevent the packing bore from leaking due to movement of the packing and backing off of the packing nut. The foregoing embodiments also provide a device and method for tightening and loosening a threaded nut in a threaded bore.

In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “left” and right”, “front” and “rear”, “upward” and “downward” and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.

In addition, the foregoing describes only some embodiments of the disclosure, and alterations, modifications, additions and/or changes can be made thereto without departing from the scope and spirit of the disclosed embodiments, the embodiments being illustrative and not restrictive.

Furthermore, disclosures have been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the disclosure(s). Also, the various embodiments described above may be implemented in conjunction with other embodiments, e.g., aspects of one embodiment may be combined with aspects of another embodiment to realize yet other embodiments. Further, each independent feature or component of any given assembly may constitute an additional embodiment. 

What is claimed is:
 1. A locking apparatus for preventing a nut from disengaging from a bore of a device, the locking apparatus comprising: a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces; a non-movable pin extending from the bottom surface, the non-movable pin insertable into a first aperture of a nut; a retractable pin movable along a central axis of the aperture between an engaged position in which the retractable pin extends at least partially from the bottom surface, for positioning the retractable pin into a second aperture of a nut, and a retracted position, for removing the retractable pin from a second aperture of a nut to facilitate removal of the body; and a shank extending from the top surface of the body.
 2. The locking apparatus of claim 1, wherein the central axis is in a same plane as an axis of the non-movable pin.
 3. The locking apparatus of claim 1, wherein the central axis intersects an axis of the non-movable pin.
 4. The apparatus of claim 1, further comprising a resilient member to bias the retractable pin toward the engaged position.
 5. The locking apparatus of claim 1, further comprising a resilient member disposed within the shank, the resilient member biasing the retractable pin toward the engaged position.
 6. The locking apparatus of claim 1, wherein the body is arcuate.
 7. The locking apparatus of claim 1, further comprising a planar surface on an outer end of the shank, opposite the body, the planar surface adapted to transfer a rotational force to the nut.
 8. The locking apparatus of claim 1, further comprising a handle extending from the retractable pin to retract the retractable pin.
 9. A method of manufacturing a locking apparatus for preventing a nut from disengaging from a bore of a device, the method comprising: providing a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces; securing a fixed pin to the body such that the fixed pin extends in fixed relation from a bottom surface of the body and configured to be insertable into a first aperture of a nut; positioning a retractable pin within the aperture such that the retractable pin is movable along a central axis of the aperture between an engaged position, for positioning the retractable pin into a second aperture of a nut, and a retracted position, for removing the retractable pin from a second aperture of a nut to facilitate removal of the body; and securing a shank to a top surface of the body opposite the bottom surface.
 10. The method of claim 9, further comprising providing a body having an aperture such that the central axis of the aperture is in a same plane as an axis of the fixed pin.
 11. The method of claim 9, further comprising providing a body having an aperture such that the central axis of the aperture intersects an axis of the fixed pin.
 12. The method of claim 9 further comprising providing a resilient member to bias the retractable pin toward the engaged position.
 13. The method of claim 9, further comprising positioning a resilient member inside the shank, the resilient member biasing the retractable pin toward the engaged position.
 14. The method of claim 9, wherein securing a fixed pin to a body further comprises securing the fixed pin to an arcuate body.
 15. The method of claim 9, further comprising forming a planar surface on an outer end of the shank, opposite the body, the planar surface configured to transfer a rotational force to the nut.
 16. The method of claim 9, further comprising securing a handle to the retractable pin to retract the retractable pin.
 17. A reciprocating pump assembly, the assembly comprising: a reciprocating pump; a threaded member in engagement with a threaded bore on the reciprocating pump; a lock for resisting movement of the threaded member relative to the reciprocating pump, the lock comprising: a body having a top surface, an opposed bottom surface and an aperture extending at least partially between the top and bottom surfaces; a first pin non-rotatably attached to and extending from the bottom surface of the body for engagement with the threaded member; a second pin at least partially disposed within the aperture and movable relative to the body between an engaged position, where at least a portion of the second pin is configured to engage the threaded member to secure the body to the threaded member, and a retracted position, to facilitate separation of the body from the threaded member; and a shank extending from the top surface.
 18. The reciprocating pump assembly of claim 17, further comprising a resilient member to bias the second pin toward the engaged position.
 19. The reciprocating pump assembly of claim 17, further comprising a resilient member disposed within the shank, the resilient member biasing the second pin toward the engaged position.
 20. The reciprocating pump assembly of claim 17, further comprising a handle extending from the second pin to retract the second pin.
 21. The reciprocating pump assembly of claim 17, wherein the threaded member comprises at least one aperture to receive at least one of the first or second pin therein.
 22. A nut lock comprising: a main body having a top surface, an opposed bottom surface, and an aperture extending at least partially through the main body; a shank extending from a top surface of the main body; a non-movable member extending from the bottom surface of the main body and configured to engage a nut; and a movable member movable between an engaged position, wherein the movable member extends from the main body and is configured to engage a nut such that rotation of a nut is prevented, and a disengaged position, wherein the movable member is at least partially retracted with respect to the main body and is configured to be disengaged from a nut. 